[gorkish]

IMO simply being reflective is a dead end. Future materials will have to absorb wideband energy and actively emit it in an atmospheric bandgap to be effective enough to matter. I would think this would be an excellent application for quantum dots and have been sort of low-key waiting for an announcement or paper to drop for the last year or two.

[rickydroll]

We also need to reduce aircraft contrails. Contrails increase high-altitude clouds (cirrus and related), which blocks the heat that would have been lost by radiative cooling. It isn't hard to reduce contrails. We have the atmospheric data telling us the height of and where clouds are likely to form. Aircraft need to change altitude by 2000 ft from what was planned to avoid the cloud-forming regions.

research paper https://acp.copernicus.org/articles/19/8163/2019/

AI is helping reduce the problem https://blog.google/technology/ai/ai-airlines-contrails-clim...

[piyh]

Reducing contrails would cause more warming unless we have a ton of these coatings out there

[rickydroll]

That's not how clouds in the atmosphere work. Lower clouds reflect infrared back up and away from Earth. When large oceangoing vessels reduce their soot emissions, the formation of low altitude clouds declined letting more infrared in to the surface and increase the amount of heating in the lower atmosphere and surface of the earth. On the other hand, contrails hold heat in and prevent it from radiating out into space.

The "ideal" situation would be lots of low altitude clouds and no high-altitude clouds like Cirrus and contrails. This conjecture comes from the known property of low altitude clouds reflect the heat up and eliminated heat retention properties of high-altitude clouds.

For more detail:https://earthobservatory.nasa.gov/features/Clouds#:~:text=Lo....